DE3306312A1 - MOVABLE CLUTCH OR BRAKE DISC FOR AN ELECTROMAGNETIC CLUTCH OR BRAKE - Google Patents

Description

Telephone (089) 44 (32496

Telex 5215935

Telegrams patemus munich

Post check Munich 39418-802

Reuschelbank Munich 2803007

Patent attorney Dr.-Ing. R. Liesegang admitted to the European Patent Office - admitted to the European Patent OMice - Mandataire agree aupres Γ Office Europeen des Brevets

Movable clutch or brake disc for an electromagnetic clutch or brake

The invention relates to a movable clutch or brake disc for an electromagnetic clutch or Brake according to the preamble of claim 1.

The purpose of the invention is to prevent a scraping or scratching noise from such a movable disk or to reduce. In particular, this should be done in the case of a movable clutch or brake disk of an electromagnetic Clutch can be achieved in which the clutch and braking functions by axial movement the movable disc is to be exercised alone without bending at the time of actuation.

In general, the scratching or scraping phenomenon in an electromagnetic friction clutch or brake leads to a unpleasant noise at the time of actuation, depending on the condition of the braking surfaces and other factors may occur or not. In a device such as a drive for a sewing machine, in which an operator sits on the side of the sewing machine, results from the scratching or scraping noise described a great nuisance and nuisance for the operator.

To prevent the scratching or scraping noise, the

ORIGINAL INSPECTED

of Japanese Patent Application 31311/1977 proposed measures. These measures are explained below with reference to FIG. In the drawing denotes the Reference number 1 a friction lining which is attached to a movable armature 2; reference numeral 3 denotes a elastic component attached to the opposite side to the side glued to the friction lining 1, and the reference numeral 4 denotes a face plate made of metallic material, which is applied to the elastic member 3 is glued on. The reference number 10 generally designates the movable disc with the friction lining 1, the rotatable one Armature 2, the elastic component 3 and the end plate 4 made of metallic material. Numeral 6 denotes a in the longitudinal direction extending groove on the inner circumference of the rotatable armature 2. By means of this groove 6 can move the movable disk 10 axially along a wedge (not shown) on the output shaft and thus generate the clutch or braking effect.

A representation of this construction on a model is shown in Fig. 2, the spring constant of the elastic Component 3 with K, the damping coefficient of the viscous. Damping is denoted by C and the mass of the end plate 4 made of metallic material is denoted by m2. m1 denotes the mass of the rotatable anchor 2.

The following explains how the scratching or scraping noise is avoided in this conventional design. Thereby the scratching or scraping noise by attaching a vibration damper in layer form with the elastic component 3 and the end plate 4 reached on metallic material, which is glued to the elastic component 3 to a uniform To create a component with the armature 2, the named parts taking part in the friction movement and the friction lining 1

ORIGINAL INSPECTED

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the anchor 2 is glued, and by improving the

periodic damping of the component due to its viscous damping. This is in the model representation drawn according to FIG. As described in the aforementioned Japanese patent application, the mass m2 without the Front plate 4 made of metallic material extremely small, whereby the periodic damping characteristic is considerable sinks. This follows easily from the vibration theory based on this model.

When a certain exciting force is applied to the disk 10 described above, which based on the theory the conventional design is designed, according to test results, a periodic damping according to Fig.

achieved. It could also be shown experimentally that that when the front plate 4 is made of metallic material, a periodic attenuation behavior results Fig. 4 sets.

in Figs. 3 and 4, the ordinate is the amplitude and the time is plotted along the abscissa. The diagrams show that the periodic damping in Fig. 3. Faster than in Fig. 4 is going on. In other words, it can be confirmed that the mass m.2 of the face plate 4 made of metallic material makes a major contribution to periodic damping.

The construction described above is used, among other things, to prevent the scratching or scraping noise of the movable Disc used in practice in a conventional electromagnetic clutch or brake. If, in doing so, an attempt is made to accelerate the periodic damping and the effect of preventing the scratching or scraping noise due to the fact dnß the mass m2 of the front plate 4 made of metallic

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Material is too small, it turns out that the periodic damping of the face plate is tedious and no prevention of scratching or scraping noise can be achieved, so that the mass of the face plate 4 _{made of} metallic material must inevitably be made large, which increases the inertia of the moving disc in its entirety.

According to the conventional practice, the disadvantage is inevitable that in a motor with an electromagnetic Clutch or brake that is used in a device such as a sewing machine drive, which is a steep Must have a speed increasing characteristic, the inertia of the output side becomes large, and therefore it is not satisfactory steep increase in speed can be achieved.

Other measures for preventing the scratching or scraping noise are explained with reference to FIG. 5. The reference number 1 denotes therein an armature which can be rotated on a rotatable basis glued friction lining, the reference number 3 a rubber-like elastic component, which on the to the with the friction lining 1 provided side of the armature 2 facing away from the armature 2 is glued, and the reference number 4 a Front plate made of metallic material to prevent peeling of the rubber-like elastic member 3 from Armature 2 under the influence of the heat generated thereby, the end plate 4 covering the entire free surface of the rubber-like elastic component 3 covers. Reference numeral 5 denotes a screw for securing the face plate 4 on the rotatable anchor ring 2. The metal end plate 4 and the rubber-like elastic component 3 are not glued together. Reference number 10 denotes as a whole the movable disc with your rotatable armature 2, the rubber-like elastic component 3, the end plate made of metallic material and the screw 5.

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number 6 denotes a groove along the inner circumference of the rotatable armature 2. By means of this groove 6, the movable disc 10 can be moved along a wedge (not shown) move axially on the output shaft to enable the clutch or braking effect.

In the following, the function of the construction according to FIG. 5 for preventing a scratching or scraping noise explained. In this construction, instead of being stapled together of the elastic component 3 and the end plate 4 made of metallic material as in the case of the aforementioned Japanese patent application 31311/1977 the screw connection 5 for directly connecting the face plate 4 metallic material provided with the armature 2.

With regard to the periodic damping described above, the face plate 4 is not made of a metallic material glued to the elastic component 3 described above, which is why the mass m2 in FIG. 2 is extremely small and their periodic damping ability is significantly reduced is. When a certain excitation force is applied to the movable disc 10 according to the conventional construction Fig. 5 is applied, a periodic damping according to FIG. 6 is generated.

In FIG. 6, the amplitude is plotted along the ordinate and the time is plotted along the abscissa. From this graph it can be seen that the periodic damping is very similar to that as si.e with reference to the Japanese patent application 31311/1977 in Fig. 4 without the involvement of the front plate 4 made of metallic Material is shown.

In other words, in the conventional construction according to FIG. 5, it can be determined that from

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Finally, the rubber-like elastic component 3 contributes to the periodic damping, while the end plate made of metallic material makes no contribution to the periodic damping.
5

This further construction to prevent scratching or Scraping noise of the moving disc for one electromagnetic clutch or brake is designed as described above.

In this case, the periodic damping is tedious and a preventive effect against scratching or Scraping noise is not achieved to a large extent. Furthermore, since the face plate 4 made of metallic material for preventing the rubber-like elastic member 3 from peeling off from the movable armature 2 is arranged the inertia of the movable disc 10 increases as a whole. With the conventional one designed as described Construction therefore has several disadvantages, such that it is not a satisfactory one A speed increase characteristic can be achieved in a device such as a sewing machine drive which a steep increase in speed and prevention of scratching or scraping noise is required because the inertia of the driven side is increased, and that the device cannot be designed so that it it is only very difficult to generate a scratching or scraping noise.

The invention is intended to address the various disadvantages of the conventional construction as described can be prevented and a movable disc for an electromagnetic clutch or brake schalfen which are particularly suitable for driving a device such as a sewing machine drive

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is suitable, the low inertia, fast periodic damping, a steep speed characteristic and a high preventive effect against the scratching or scraping noise and a preventive effect against the generation of a has such a noise.

According to the invention, this is with a movable Clutch or brake disc of the type described in the preamble of claim 1 provided that the Front plate has a smaller surface than the entire free surface of the elastic component and with the rotatable armature is directly connected and that the elastic component of the end plate against the end face of the movable armature is biased, so not by means of an adhesive with this end face of the movable Anchor is connected.

The invention is described below with reference to schematic drawings of the prior art and of exemplary embodiments explained in more detail with further details. Show it:

1 shows a cross section through a conventional movable clutch or brake disk; Fig. 2 is a model representation of the conventional one

Embodiment according to FIG. 1; Fig. 3 is a diagram showing the periodic Shows damping of the conventional movable disc of Figure 1; Fig. 4 is a diagram showing the periodic

Damping of the conventional movable disc of Fig. 1 without provided thereon Metal plate shows;

Figs. 5A and 5B show another conventional movable disk, with Fig. 5A being broken away

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Front view and FIG. 5B show a half section in the axial direction;

Fig. 6 is a diagram in which the periodic

Damping of the conventional movable disc of Figures 5A and 5B is shown; FIGS. 7A and 7B show an embodiment of a movable disk according to the invention, FIG. 7A a front view and FIG. 7B show a half section in the axial direction; Fig. 8 is a diagram in which the periodic

Damping of the movable disc of Figures 7A and 7B is shown;

9A and 9B show another embodiment of a movable one

Disk according to the invention, FIG. 9A being an end view and FIG. 9B being a half

section in the axial direction, and

Fig. 10 is a diagram in which the periodic

Damping of the movable disc is shown in FIGS. 9A and 9B. 20th

In the following the invention is based on a preferred one Execution according to FIG. 7 explained.

Reference number 1 denotes a friction lining which is applied to one end face of a cup-shaped, rotatable armature 2 is glued. Reference number 3 denotes an annular elastic member made of rubber and reference number 4 denotes a Front plate made of a metallic material with such an expansion that they cover the elastic component can. The reference number 4a denotes holes or openings in the face plate 4, which are given a predetermined Extend distance in the circumferential direction and comprise a total of four holes.

The elastic component 3 made of rubber is on the side

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of the rotatable armature 2, which faces away from the side carrying the friction lining 1, and against it The end face is prestressed with the holes 4a by means of the end plate 4 made of metallic material. The elastic Component 3 is neither glued to the armature 2 nor to the end plate 4 made of metallic material or in any other way attached, reference numeral 5 denotes screws for fastening the face plate 4 to the rotatable armature 2. Reference number 10 denotes as a whole the movable disk made of the friction lining 1, the rotatable armature 2, the elastic one Component 3 made of rubber, the face plate 4 made of metallic material and the screws 5. Reference number 6 denotes a groove in the axial direction along the inner circumference of the rotatable armature 2. The movable disk 10 is through Applying an electromagnetic force in the longitudinal direction fine wedge (not shown) moves, softer on the output shaft is provided in the axial direction in order to generate the clutch »- or braking effect.

In the embodiment of the invention designed in this way, it is sufficient if the end plate 4 is made of a metallic material the elastic component 3 made of rubber is only partially applied, the holes 4a within the peripheral edge the end plate are provided, with the result that the inertia of the movable disc 10 as a whole is reduced = Furthermore, it has been found experimentally that when a certain excitation force is exerted on the movable disc 10 a periodic damping according to FIG. 8 is generated. In Fig. 8 is on the ordinate the amplitude and the time on the abscissa. This periodic damping behavior is according to the diagram very similar to that, as shown in Fig. In the construction of the Japanese patent application 31311/1977 sets, whereby the periodic

- ■ * -> Damping goes faster than the diagram below

ORIGINAL INSPECTED BAD ORIGINAL "

Fig. 4, wherein a damping behavior without a faceplate made of metallic material at the aforementioned Japanese Patent application is shown, or as at Fig "6, the damping behavior of the conventional design according to Fig. 5 is shown. Therefore, the movable disk according to the invention is very effective with a view to preventing a scratching or scraping sound from being generated.

Furthermore, in the described embodiment of the invention it is not necessary that the elastic component is glued or pinned to the rotatable armature 2, as is provided in the conventional constructions of FIGS. 1 and 5, which contributes to additional Saving labor and thus manufacturing costs to lower.

FIGS. 9A and 9B show another embodiment of 'i ^ cr movable disc for an electromagnetic clutch or brake according to the invention. Differences in this version compared to the version according to FIG. 7 is that the holes or openings 4a are provided in the form of a pair and symmetrically opposite one another in the face plate 4. Otherwise, the construction is the same as in the embodiment according to Fig.

It was found experiment ie 11, that the periodic Damping behavior of the embodiment according to FIG. 9 behaves as shown in the diagram according to FIG The diagram of Fig. 10 shows that the periodic damping of the embodiment of FIG. 9 with a. Pair of holes 4a in the end plate 4 similar to the periodic damping behavior the conventional construction according to the Japanese patent application 31311/1977 as shown in Fig. 3 is, the periodic damping is faster than

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plays according to the diagrams of FIGS. 4 and 6, so that a real noticeable improvement in terms of Prevention of a scratching or scraping noise is achieved.

The better periodic damping behavior according to FIG. 8 in the embodiment according to FIG. 7 is evidently due to the periodic damping behavior according to FIG. 10 of the embodiment of FIG. 9, therefore, that the end plate 4 in the The embodiment according to FIG. 7 has a lower inertia due to the larger number of holes 4a.

Although no clear explanation on the basis of vibration theory can be given why that periodic damping behavior by reducing the inertia of the end plate 4 made of metallic material could be achieved, the vibration theory for the embodiments according to the invention is evident different from the conventional example of Japanese Patent Application 31311/1977 according to FIG. 1.

Although in the embodiments described above, the elastic component is made of rubber, can also another elastic material with similar properties as rubber z. B. cork o. The like. Used will. In the same way, the end plate can be used to pretension the elastic component apart from one metallic material also made of another material with a similar hardness, such as a synthetic resin exist. In other words, it is sufficient if the face plate has the ability to act as the elastic component to push into its desired position in order to improve the periodic damping properties when its mass is small and to produce a satisfactory preventive effect against the scratching or scraping noise, and therefore the inertia of the moving disk in its total

ORiGINAL INSPECTED

can be made small.

As stated above, there is due to the bias of the elastic member by the end plate not the need to attach the elastic member to the faceplate or the rotatable anchor, which contributes to a reduction in manufacturing costs. In addition, it is sufficient if the end plate is only a part applied to the entire elastic component, so that Holes may be provided within the inner periphery of the end plates. Because of this design, created a movable disc for an electromagnetic clutch or brake that is very suitable for Devices. And applications such as the drive of a sewing machine is because they have the required low inertia, fast periodic damping properties, a high preventive effect against scratching or scraping noise, has a steep speed increase characteristic and such performance characteristics that no scratching or scraping noise is generated.

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Claims (12)

I .. * .. * * * .. *.:!. * · .. ·· & -8000 Munich 80 SckelIstrasse 1 Telephone (089) 4482496 Telex 5215935 Telegrams patemus some Patent attorney Dr.-Ing. R. Liesegang admitted to the European Patent Office - Mandataire agree aupres Γ Oftice European des Brevets MITSUBISHI DENKI KABUSHIKI KAISHA
Tokyo, Japan
P 147 24 Expectations Movable clutch or brake disc for an electromagnetic one Clutch or brake with a rotatable armature (2), which can be moved in a predetermined direction by Application of electromagnetic forces is movable, a friction lining (1) · which is placed on an end face of the movable armature (2) is applied, an elastic component (3) which is attached to the friction lining face opposite end face rests, and an end plate (4) made of a comparatively hard Material which acts on the free surface of the elastic component, characterized in that, that the face plate (4) has a smaller surface than the entire free surface of the elastic Component (3) and with the rotatable armature (2) directly. is connected, and that the elastic member (3) of the end plate (4) is biased against the end face of the movable armature (2). ORIGINAL INSPECTED OOUDO I Z 2. Disc according to claim 1, characterized in that the rotatable armature (2) Is designed cup-shaped. 3. Disc according to claim 1 or 2, thereby g e character shows that the friction lining (1) is annular and in the vicinity of the outer periphery of the armature (2) is arranged. 4. Disc according to one of claims 1 to 3, characterized in that the elastic Component (3) consists of rubber. 5. Disc according to one of claims 1 to 3, dadui-ch ge marks ichnet that the elastic component (3) consists of cork. 6. Disc according to one of claims 1 to 5, marked by that the end plate (4) consists of metallic material. 7. Disc according to one of claims 1 to 5, characterized characterized in that the end plate (4) consists of a synthetic resin. 8. Disc according to one of claims 1 to 7, characterized in that the end plate (4) is attached to the armature (2) by means of screws (5). 9. Disc according to one of claims 1 to 8, characterized in that holes {4a) are formed in the end plate (4) to support the mass of the end plate and its elastic component (3) to reduce the covering area. ORIGINAL INSPECTED 10. Disc according to claim 9, characterized in that g · e k e η η that the end plate (4) is annular and coaxial with the axis of rotation of the armature (2) is arranged, and that the holes (4a) are symmetrical with respect to the axis of rotation. 11. Disc according to claim 9 or 10, characterized in that g e t that the end plate (4) has four elongated holes (4a) which extend in the circumferential direction extend with respect to the axis of rotation. 12. Disc according to one of claims 9 to 11, characterized in that a plurality of screws (5) to attach the end plate (4) to the anchor (2) on a circle with a predetermined radius and with the center in the axis of rotation of the anchor (2) are provided. ORIGINAL INSPECTED